Philippians 1:19

Philippians 1:19. For I know that this shall turn to my salvation. The apostle means by ‘this' the whole course of opposition from which he was made to suffer. For though he is joyful that Christ is preached by any means, yet he would be much more rejoiced were it all done in purity of spirit. Therefore his rejoicing is not without its attendant pain. But he will make the opposition an occasion for more fervency of spirit and purity of motive on his own part, and thus he will be carried onward in the work of his own salvation.

through your supplication. He is sure that when the Philippians know of his affliction from these jealousies of insincere Christians, they will give him their prayers, and that these will be answered by a greater outpouring of grace in his time of need.

and the supply of the Spirit of Jesus Christ. This was the only true relief in his trouble, more of the Spirit of Jesus Christ. So will his own work in preaching Christ's Gospel be purified and made effective.